"Dec 28 7:11 AM We disabled payouts last night after reports of multiple user accounts being compromised. The issue and the users affected were identified and Multipool will be reimbursing any funds that were lost as a result of the attack. We'll be contacting affected users directly via email and also locking down some additional accounts that could have potentially been compromised. Payouts should be processing again shortly. Thanks for your patience."

That explains it...